CBOE Stock Exchange Single-Day Volume Tops 50 Million Shares For The First Time On August 1 - July Trading Of 350 Million Shares Was New All-Time High

CBSX, the CBOE Stock Exchange, LLC, a subsidiary of the Chicago Board Options Exchange (CBOE), announced that single-day trading volume of 50,205,700 shares on Friday, August 1, 2008 marked the first time CBSX has surpassed 50 million shares traded.

Additionally, trading volume during the month of July totaled 350,075,476 shares, with an average daily volume of 15,912,522 shares per day, both new high marks for CBSX.The previous record was 261,984,616 shares traded in January 2008.July 2008 volume exceeded the 108.9 million shares traded last July by 207 percent.For the month, a total of 380,879 trades were executed at CBSX, compared to 195,032 trades from a year-ago.

"CBSX continues to deliver on its mission to provide a marketplace that reduces CBOE options traders' stock execution costs by offering direct connectivity to CBSX, enhanced functionality, and value-added, lower-cost services," said David Harris, CBSX's Chief Executive Officer. "Now into our second year of operation, we are gratified that volume, liquidity and market share are building steadily - an endorsement of CBSX's business model and goal to offer a stock market where options hedging is faster, cheaper and better."

CBSX launched an automated buy-write feature in February that allows CBOE and CBSX order flow sending firms to send a "stock-option package" electronically, facilitating faster and more efficient executions.The automated buy-writes offer the benefits of price improvement on the options side, combined with immediate printing on the stock side -- all available at a lower cost than what customers might currently pay now at other exchanges.

CBOE Stock Exchange (CBSX) is a fully electronic, Regulation NMS compliant marketplace, offering strict price-time priority for all participants. CBSX offers trading in 4,422 of the most actively traded New York Stock Exchange, American Stock Exchange and NASDAQ Stock Market listed and Over-the-Counter securities as well as Exchange Traded Funds (ETFs).Launched in March 2007, CBSX is a subsidiary of the Chicago Board Options Exchange (CBOE).For more information about CBSX, including listings, access and fees, visit www.cbsx.com.